Hay fever is believed to be caused by allergens in the air such as dust, spores, and animal dander. Traditionally, early people associate harvesting of field hay to developing constant sneezing and chronic fever, thus the term “hay fever.”

However, in this age of modern medicine, this belief is said to be a misnomer. Experts say that a fever that is caused by certain allergens should not be hastily associated with a mere contact with field hay.

The more common term for hay fever, today, is allergic rhinitis. The term has been introduced because it is a more appropriate term medically. ‘Rhinitis’ refers to the irritation of the nasal passages that is connected to sneezing, nasal congestion, itchy eyes and nose, runny nose and excess tears. Sometimes, when put together, these symptoms can bring on an unusually high temperature.

When the body’s immune system is attached by these allergens, that’s when hay fever occurs. Within the body’s immune system, there is a productive substance called the ‘immunoglobuline E’ or IgE. Allergic rhinitis begins when the antibodies (allergens) begin to hurt mast cells. The group of cells are sometimes unprotected by IgE because they are so many that the IgE supply can’t cover them all up against all of the antibodies.

When mast cells become infected, they produce allergic substances toward tissues and other body cells. Histamine is one of these substances. It is a very strong and sometimes irritating substance that can cause extreme itchiness and some swelling to the tissues.

In the long run, these substances, like histamine, could trigger a lot more mechanisms to cause more serious disorders like tightening of the throat, loss of voice, and more seriously, asthma. Sometimes, sufferers of hay fever experience muscle spasms and lung contraction.

Allergic rhinitis is also proven to be specifically caused by proteins. Individuals who always come in close contact with plants might be infected with proteins called pollens, the known male sex cells in weeds, trees, and grasses. Pollen is usually invisible since it is only about 4 microns in diameter.

The most potent source of allergies is pollen. This is probably because we can’t really see it because of it’s size. These pollens rest on nasal passages and can affect the entire respiratory tract, and this in turn causes allergic reactions.